literally, A way of life is he that keepeth instruction. The verb "erreth" is better rendered in the margin. The influence for good or evil spreads beyond the man himself.

He is in the way of life - The truly religious man accumulates knowledge that he may the better know how to live to God, and do most good among men.

He is in the way of life,.... Of eternal life, which is truly, properly, and by way of eminency, "life", Matthew 19:17; and which is a life of glory; a life of perfection, of perfect holiness, knowledge, obedience, love, peace, and joy; a life free from all the inconveniences of the present life, animal or spiritual; a life of pleasure, and which will last for ever: the "way" to it is not by works of righteousness done by men, since by these the law is not fulfilled, nor justice satisfied; and therefore no justification of life by them, or what entitles to eternal life; it is sinful, dangerous, and a vain thing, to seek for eternal life in this way; Christ is the only true way to it; who, by his obedience, sufferings, and death, has opened the new and living way; and through his blood, righteousness, and sacrifice, way is made for all that believe in him to enter into eternal life: and such are in the way to it who are in Christ, secretly in election, openly in the effectual calling; when they are made new creatures, are quickened by the Spirit and grace of Christ, and have that principle in them which is a well of living water, springing up unto everlasting life; who have a sight of Christ, and come unto him by faith; who truly believe in him, with which eternal life is connected. Particularly he is in the way unto it
that keepeth instruction; the instruction in righteousness which the Scriptures give, especially the Gospel part of them; which is an instruction into the mind and will of God about man's salvation; into the grace of God, as displayed therein; into the person and offices of Christ, and salvation by him; into the doctrines of peace, pardon, righteousness, and life, through him. Now he to whom this instruction comes with power, and is the savour of life unto life; who receives it in the love of it; who "observes" (i) it, as the word here used signifies; takes notice of and follows its direction, pointing out Christ as the way of salvation, instructing to look to him and believe in him, and be saved; and who retains and holds fast such instruction, and abides by it; and finds the word of the Gospel, and eats it, and is nourished by it unto everlasting life; he is most assuredly in the way of it;
but he that refuseth reproof erreth; that is, from the way of life. He that rejects the counsel and advice, the admonitions and reproofs, given in the word of God, by the ministers of it; or by parents and masters, friends or relations, that wish him well; he wanders far off from the way that leads to life, and goes into the paths of sin, and consequently is in the way of death. Some render it, "causeth to err" (k); either others, as Aben Ezra; or both himself and others, as Jarchi: and then it may be understood of him "that forsaketh reproof" (l), as it may be rendered; that is, that declines giving reproof, when it lies in his way, and is his duty to do it. Aben Ezra reads this clause in connection with the former, as said of one and the same person,
"he is in the way of life that keepeth instruction, and forsakes or rejects the reproof of him that causeth to err.''
(i) "observat", Tigurine version; "servat", Cocceius; "observans", Schultens. (k) "faciens errare", Montanus, Gejerus; "seduceus sese", Tigurine version; "errare facit", some in Vatablus; "facit oberrare", Cocceius. (l) "qui relinquit increpationem", Pagninus; "deserens", Montanus, Schultens; "derelinquit", Piscator; "deserit", Cocceius.

The traveller that has missed his way, and cannot bear to be told of it, and to be shown the right way, must err still.

keepeth--observes (Proverbs 3:18; Proverbs 4:22).
refuseth--or, "turns from reproof," which might direct him aright.

The group of proverbs now following bring again to view the good and bad effects of human speech. The seventeenth verse introduces the transition:
17 There is a way to life when one gives heed to correction;
And whoever disregards instruction runs into error.
Instead of ארח חיּים (Proverbs 5:6), there is here ארח לחיים; and then this proverb falls into rank with Proverbs 10:16, which contains the same word לחיים. The accentuation denotes ארח as subst.; for ארח way, road = ארח [a wayfarer, part. of ארח] would, as שׁסע, Leviticus 11:7, נטע, Psalm 94:9, have the tone on the ultima. It is necessary neither to change the tone, nor, with Ewald, to interpret ארח as abstr. pro concreto, like הלך, for the expression "wanderer to life" has no support in the Mishle. Michaelis has given the right interpretation: via ad vitam est si quis custodiat disciplinam. The syntactical contents, however, are different, as e.g., 1-Samuel 2:13, where the participle has the force of a hypothetical clause; for the expression: "a way to life is he who observes correction," is equivalent to: he is on the way to life who...; a variety of the manner of expression: "the porch was twenty cubits," 2-Chronicles 3:4, particularly adapted to the figurative language of proverbial poetry, as if the poet said: See there one observant of correction - that (viz., the שׁמר [שׁמר, to watch] representing itself in this שׁמר) is the way to life. מוּסר and תּוכחת are related to each other as παιδεία and ἔλεγχος; עזב [עזב, to leave, forsake] is equivalent to בּלתּי שׁמר. מתעה would be unsuitable as a contrast in the causative sense: who guides wrong, according to which Bertheau understands 17a, that only he who observes correction can guide others to life. We expect to hear what injuries he who thinks to raise himself above all reproach brings on himself. Hitzig, in his Commentary (1858), for this reason places the Hithpa. מתּעה (rather write מתּעה) in the place of the Hiph.; but in the Comm. on Jeremiah (1866), 42:20, he rightly remarks: "To err, not as an involuntary condition, but as an arbitrary proceeding, is suitably expressed by the Hiph." In like manner הוסיף, הגּיע (to touch), הרחיק (to go to a distance), denote the active conduct of a being endowed with reason; Ewald, 122, c. Jewish interpreters gloss מתעה by supplying נפשׁו; but it signifies only as inwardly transitive, to accomplish the action of the תּעות.